title: Toward validation of the cepstral spectral index of dysphonia (CSID) as an objective treatment outcomes measure.
abstract: OBJECTIVE
  To examine the validity of the Cepstral Spectral Index of Dysphonia (CSID) as an objective treatment outcomes measure of dysphonia severity.
  
  
  METHODS
  Pre- and posttreatment samples of sustained vowel and connected speech productions were elicited from 112 patients across six diagnostic categories: unilateral vocal fold paralysis, adductor spasmodic dysphonia, primary muscle tension dysphonia, benign vocal fold lesions, presbylaryngis, and mutational falsetto. Listener ratings of severity in connected speech were compared with a three-factor CSID model consisting of the cepstral peak prominence (CPP), the low-to-high spectral energy ratio, and its standard deviation. Two additional variables, the CPP standard deviation and gender, were included in the five-factor CSID model to estimate severity of vowels.
  
  
  RESULTS
  CSID-estimated severity for sustained vowels and connected speech was strongly associated with listener ratings pretreatment, posttreatment, and change observed pre- to posttreatment. Spectrum effects were examined, and severity of dysphonia did not influence the relationship between listener perceived severity and CSID-estimated severity.
  
  
  CONCLUSIONS
  The results confirm a robust relationship between listener perceived and CSID-derived dysphonia severity estimates in sustained vowels and connected speech across diverse diagnoses and severity levels and support the clinical utility of the CSID as an objective treatment outcomes measure.
authors.affiliation: Department of Communication Sciences and Disorders, The University of Utah, Salt Lake City, Utah 84112, USA. Peterson.elizabeth.anne@gmail.com
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Peterson
authors.forename: Nelson
authors.initials: N
authors.lastname: Roy
authors.forename: Shaheen N
authors.initials: SN
authors.lastname: Awan
authors.forename: Ray M
authors.initials: RM
authors.lastname: Merrill
authors.forename: Russell
authors.initials: R
authors.lastname: Banks
authors.forename: Kristine
authors.initials: K
authors.lastname: Tanner
mesh_terms: D000162:Acoustics; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D055154:Dysphonia / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D012815:Signal Processing, Computer-Assisted; D013061:Speech Acoustics; D013067:Speech Perception; D013068:Speech Production Measurement / Q000379:methods*; D014833:Voice Quality; D055815:Young Adult